1. Field of the Invention
The present invention relates to an access control system and an access control method thereof. More particularly, the access control method of the present invention generates a one-time password (OTP) for use by a handheld device and a terminal recording device to perform a two-way identification certification therebetween so that the handheld device can access data of the terminal recording device after the two-way identification certification has been successfully completed.
2. Descriptions of the Related Art
An advanced metering infrastructure (AMI) system is a system comprising electricity meter devices, a communication system, a data management server and so on. The AMI system can measure and collect energy consumption information, and support pricing of consumers of the critical peak pricing (CPP) plan so that the users can know the energy consumption statuses and save energy. Additionally, the AMI system can further support fault detection, blackout management and consumer power consumption quality management, improve accuracy of the line loss calculation, reduce regional line congestions and reduce the unbalanced usage statuses.
Because the communication mechanism between the electricity meter devices and the data management server has such problems as instable network connection accessing capability, a low connection speed and a small data amount (i.e., in a limited connection status), it is not always possible for the remote data management server to keep stable connections with the electricity meter devices to exchange information. When the remote data management server fails to connect with the electricity meter devices, data access to the electricity meter devices must be accomplished manually at the near end. Most of conventional technologies of manually accessing the electricity meter devices adopt fixed keys to perform identification certification with the electricity meter devices. However, the invariable keys are easy to be divulged, cracked or stolen, so some people may deliberately access the electricity meter devices by using the fixed keys illegally.
In view of this, an urgent need exists in the art to provide an effective and safe way of certification for near-end accessing when the remote data management server fails to connects with an electricity meter device in a limited connection status.